[PhineasRex]

To be fair, that's really more of a python-specific deficiency than a general problem with significant whitespace. Haskell for example interprets further-indented lines as a continuation of the current expression, only ending the expression when it sees a new line of the same or lesser indentation.

[ReleaseCandidat]

As I wrote, you have to do similar things when using Haskell (or F# or OCaml) in the REPL. Python just doesn't have a special 'non-REPL' syntax.